3 Nephi 12: 7:
“And blessed are the merciful, for they shall obtain mercy.”
The standard applied to us is the standard we apply to others. This is repeatedly set out in scripture:
Alma teaching his son Corianton recorded: “Therefore, my son, see that you are merciful unto your brethren; deal justly, judge righteously, and do good continually; and if ye do all these things then shall ye receive your reward; yea, ye shall have mercy restored unto you again; ye shall have justice restored unto you again; ye shall have a righteous judgment restored unto you again; and ye shall have good rewarded unto you again. For that which ye do send out shall return unto you again, and be restored; therefore, the word restoration more fully condemneth the sinner, and justifieth him not at all.” (Alma 41: 14-15.)
Moroni’s final discussion about the Gospel included these words: “And now, my brethren, seeing that ye know the light by which ye may judge, which light is the light of Christ, see that ye do not judge wrongfully; for with that same judgment which ye judge ye shall also be judged.” (Moroni 7: 18.)
Peter asked a practical question about the extent of forgiving others. He wanted a mathematical limit to be set. The Lord, however, raised the limit beyond an ability to reasonably count: “Then came Peter to him, and said, Lord, how oft shall my brother sin against me, and I forgive him? till seven times? Jesus saith unto him, I say not unto thee, Until seven times: but, Until seventy times seven.” (Matt. 18: 21-22.)
There are others. I’d commend the chapter on the Atonement in Come, Let Us Adore Him for a more complete explanation of this doctrine.
If you want mercy from the Lord, you must give it to your fellow man. If you do not show mercy to your fellow man, the Lord cannot provide it to you. There is a law which binds the Lord to the same standard you set for yourself. It is an irrevocable law. Therefore, the Lord teaches us to show mercy so that we might merit mercy. We are the final beneficiaries of all the mercy we show to others.
It really is true that “what you send out shall return unto you again,” to quote Alma. This is called “karma” in another faith. It is a true principle. Perhaps it operates within an larger time frame than just this life, but it operates, nonetheless. Alma knew the truth and was teaching it to his son.
It was Laban’s judgment of Nephi and his brothers that got him killed. I’ve discussed this in The Second Comforter. It was his decision that a robber was worthy of death (1 Nephi 3: 13) which sealed his fate. For when he became a robber (1 Nephi 3: 25), then the Lord was free to show him the same judgment he had rendered (1 Nephi 4: 11). Sometimes what you send out returns to you again in this life